1. Field of the Invention
The present invention relates to a brushless D.C. motor assembly, and more particularly to a rotor thereof, in a poised position with more stable rotational movement.
2. Description of the Related Art
A conventional brushless D.C. motor assembly comprises a rotor provided with an axle rotatably supported by several bearings disposed within an axle tube of a stator such that the rotor can rotate smoothly.
For the sake of the requirement of assembly, a gap is formed between the axle and the bearing after the assembly of the motor assembly. Although the gap is very small, the centrifugal force still can make the axle slant slightly when the axle is loaded with the weight of the permanent magnet, the blade, the wheel or other burden to rotate such that the contact between the axle and the bearing becomes uneven. Accordingly, after a long term of use, the gap will increase gradually such that the slant angle of the rotating axle is becoming bigger, thereby bringing the problems of deflection, vibration, friction, noise, etc.